New Digital Prototyping Features (Inventor In-Depth Tutorial)

Industry experts have extolled the virtues of digital prototyping to validate design ideas and support product innovation without a massive investment in R&D or physical models that fail. Recent research suggests it's true: The Digital Product Development Benchmark Report (Aberdeen Research, March 2007) indicates that best-in-class manufacturers saved several thousand dollars or more and gained at least a two-week advantage on the competition by using digital prototyping.

In practice, however, digital prototyping is more than a simple shift in process. Global manufacturers such as Boeing and Mercedes-Benz are nearly ready to or have just introduced products that benefited from digital prototyping.

What's taken so long? For one thing, parametric design applications provide model documentation without a model of the underlying physics that affect motion and function. That dynamic simulation is crucial to digital prototyping.

Prototyping Form and Function
Inventor 2008 provides a missing link. It helps engineers focus on the functional requirements of a problem -- such as layout, shaft, belt drive, and machine frame -- and create intelligent 3D models and geometry. The difference is important, when nearly all 3D solid modeling applications force engineers to create geometric models that reflect form and fit, without insight into how the design is going to perform.

More than ever, the latest Inventor software reflects the way that engineers like to solve problems of product function. Here are just a few of the enhanced features and functions that help bring digital prototyping within closer reach of companies of all sizes.

Finite Element Analysis
Virtual stress analysis can show how components and materials are likely to function in response to pressure, temperature, wind, and other physical forces associated with a product's operation. Inventor 2008 enhancements make finite element analysis (FEA) more efficient and easier to customize. Improvements include:

A new thin shell element that delivers faster results than standard 3D tetra elements in thin-walled or constant-thickness parts evaluation.

Stress-analysis environment support for feature suppressions independent of the original part or sheet-metal model, for more efficient meshing.

Capacity to explore analysis results based on loads at multiple time points in a dynamic simulation cycle, without having to switch back to dynamic simulation for each time step.

Design Accelerators
Several component generators and mechanical calculators have been updated with new interfaces and interactive dynamic preview capabilities to save users even more time constructing digital prototypes.

For instance, the Shaft Generator now includes a full 3D preview with 3D grips, which make it easy for users to grab and adjust shaft length or diameter. The Shaft Generator dialog box gives users a choice of the element type and allows specification of internal geometry and element features. Shaft parameters are automatically transferred to the Calculations tab so that engineers can define loads, bending moments, and torques and then calculate rigid stress analysis under set conditions.

Cable Routing
It's hard to anticipate whether complex electrical wiring will hinder a physical prototype, much less see what's causing the problem. A digital prototype helps engineers simulate performance and even visualize interferences that wouldn't otherwise be visible.

With the introduction of ribbon-cable functionality, including control over the insertion, routing, and shape of the cable, Inventor 2008 Professional and Inventor 2008 Routed Systems Suite have the wiring aspect of digital prototyping all wrapped up. The applications' new capabilities help maintain consistency between the electrical schematic and 3D wire harness design.

For example, users simply choose start and end points and the Create Ribbon Cable tool automatically generates a ribbon cable that's easily manipulated into folds and twists. Ultimately, that accuracy helps reduce mistakes in production as well.

More Productive Sketching
Inventor 2008 includes updates that make quick work of sketching and capturing design intent in the initial stages of product concept development. Digital capture of intent provides a point of reference that is easy to share and evolve based on insights from the digital prototype -- in turn, speeding design iteration.

For example, Inventor software now lets users identify constraints by pointing at an object in a sketch. The software shows what limits must be applied for a complete, fully constrained sketch. This insight provides greater control and accessibility to the individual constraint types as well.

For editing sketch geometry, Inventor 2008 has an extended toolset:

Move and Rotate tools feature dynamic preview, constraint, and dimension override capabilities as well as direct access to the Precise Input tool. A new Copy tool provides an alternative to using the Move tool to duplicate geometry.

A new Stretch tool supports additional ways to stretch constrained geometry with more predictable results.

The new Scale tool allows designers to change the size of 2D sketch geometry quickly by selecting the geometry and specifying a scale factor to increase or shrink it.

Design Compatibility and Interoperability
At its very core, digital prototyping depends on file compatibility and software interoperability to blend form, fit, and function. If you read Bill Fane's April review of Autodesk Inventor 2008, then you know that Inventor 2008 reads and writes 2D DWG files. That makes it a lot easier for AutoCAD software users to incorporate 3D into their design process and make the most of legacy drawings and AutoCAD expertise.

To simulate form, fit, and function, the tools used by industrial designers and mechanical and electrical engineers must work together as well, so Inventor software has new capabilities for importing AutoCAD surface and solid data. And, now that AliasStudio exports DWG files, product developers can count on speedy transfer of concept designs and their components, including 3D surfaces, 3D bodies, polygon meshes, and polylines, into Inventor. Teams can develop, share, and digitally test and analyze product designs to refine them and then build physical models of the best concepts.

Model Behavior
Thanks to these and other enhancements, the latest version of Inventor helps seamlessly connect the disciplines involved in product development and provides a foundation for digital prototyping. Check out some of the new features in Inventor 2008 that let your team find the best ideas without the time-consuming, expensive trial-and-error required by physical prototypes.

About the Author: Amy Bunszel

In her easy-to-follow, friendly style, long-time Cadalyst contributing editor and Autodesk Technical Evangelist Lynn Allen guides you through a new feature or time-saving trick in every episode of her popular AutoCAD video tips. Subscribe to the free Cadalyst Video Picks newsletter and we'll notify you every time a new video tip is published. All exclusively from Cadalyst!